exalate-issue-sync[bot]
commented
1 year ago Raymond Peck commented: In RequestServer you’ll find these lines:
Schema s = handle(type, route, version, parms);
PojoUtils.filterFields(s, (String)parms.get("_include_fields"), (String)parms.get("_exclude_fields"));
Response r = wrap(s, type);
return r;They call this:
case html: // These request-types only dictate the response-type; case java: // the normal action is always done. case json: case xml: { Handler h = route._handler; return h.handle(version,route,parms); // Can throw any Exception the handler throws }
There might be something slightly cleaner, but my initial thought is:
Somehow (tm) you’ll need to get the socket from Jetty passed to serve(). handle() should see if the output schema for the handler method implements StreamingOutput and if so it should call h.handle() in the handler, passing in the socket as a fourth, nullable argument.
It will say:
if (null != socket) { result = (Schema)route._handler_method.invoke(this, version, schema, socket); } else { result = (Schema)route._handler_method.invoke(this, version, schema); }
Back up in serve() if you’ve passed down a null socket you keep doing what it does now, calling wrap(); if not it will instead close the socket and return.
That’s pretty close.
The piece I don’t know is how to pass through the output stream / socket. You’’ need to look at the caller of RequestServer.serve().
You or I will also need to add an is_streaming flag to the metadata.
DinukaH2O
The point of this ticket is to support streaming large results to the HTTP client, and then add new endpoints for DownloadDataset and model export which use this feature.
The clients then need to be ported to use streaming.
Note that the old behavior should continue to work; a /bin suffix should trigger streaming binary (non-JSON) output.